Chronic exposure to water pollutant trichloroethylene increased epigenetic drift in CD4+ T cells. (May 2016) - Gilbert, Kathleen M
Aim: Autoimmune disease and CD4 + T-cell alterations are induced in mice exposed to the water pollutant trichloroethylene (TCE). We examined here whether TCE altered gene-specific DNA methylation in CD4 + T cells as a possible mechanism of immunotoxicity.Materials & methods: Naive and effector/memory CD4 + T cells from mice exposed to TCE (0.5 mg/ml in drinking water) for 40 weeks were examined by bisulfite next-generation DNA sequencing.Results: A probabilistic model calculated from multiple genes showed that TCE decreased methylation control in CD4 + T cells. Data from individual genes fitted to a quadratic regression model showed that TCE increased gene-specific methylation variance in both CD4 subsets.Conclusion: TCE increased epigenetic drift of specific CpG sites in CD4 + T cells.